class A5_1 {
  double f(double x,double y) {
    return x+y;
  }
}
class B5_1 extends A5_1 {
  double f(int x,int y){
    return x*y;
  }
}
public class E5_1 {
  public static void main (String args[]){
    B5_1 b= new B5_1();
    System.out.println(b.f(3,5));
    System.out.println(b.f(3.0,5.0));
  }
}
